input, textarea, select {
    padding: 5px;
}
.padding_20 {
    padding: 20px;
}
.operation:hover {
    text-decoration-line: underline;
}
.margin_r_10 {
    margin-right: 10px;
}
.margin_b_20 {
    margin-bottom: 20px;
}
.operation {
    color: #108EE9;
    margin-left: 10px;
}
.button {
    background: #169bd5;
    color: white;
    border: 0;
    border-radius: 3px;
    padding: 5px 10px;
    outline: none;
}